Determinants of cognitive function in childhood: a cohort study in a middle income context.

BACKGROUND: There is evidence that poverty, health and nutrition affect children's cognitive development. This study aimed to examine the relative contributions of both proximal and distal risk factors on child cognitive development, by breaking down the possible causal pathways through which poverty affects cognition. METHODS: This cohort study collected data on family socioeconomic status, household and neighbourhood environmental conditions, child health and nutritional status, psychosocial stimulation and nursery school attendance. The effect of these on Wechsler Pre-School and Primary Scale of Intelligence scores at five years of age was investigated using a multivariable hierarchical analysis, guided by the proposed conceptual framework. RESULTS: Unfavourable socioeconomic conditions, poorly educated mother, absent father, poor sanitary conditions at home and in the neighbourhood and low birth weight were negatively associated with cognitive performance at five years of age, while strong positive associations were found with high levels of domestic stimulation and nursery school attendance. CONCLUSION: Children's cognitive development in urban contexts in developing countries could be substantially increased by interventions promoting early psychosocial stimulation and preschool experience, together with efforts to prevent low birth weight and promote adequate nutritional status.

[Epidemiology of schoolchildren's cognitive development in Jequié, Bahia State, Brazil: assessment procedures and general results]. / Epidemiologia do desenvolvimento cognitivo de escolares em Jequié, Bahia, Brasil: procedimentos de avaliação e resultados gerais.

This paper describes the methodology, applicability and utility of the Raven Progressive Matrix (Raven Test) and the Brazilian Intellectual Probe (TSI), comparing them with school achievement in a typical medium-size urban community of Northeastern Brazil. 388 schoolchildren (7-17 years old) were examined, with 371 Raven tests applied. Only 231 TSIs were completed, since 106 students were illiterate. School grades were obtained for all participants. A questionnaire evaluating school resources, and teacher profiles was answered by 200 teachers. Raven and TSI test scores were highly correlated (r = 0.53, p < 0.001), but both correlated weakly with overall school grade (r = 0.22, p < 0.001 and r = 0.12, p < 0.07 respectively). For individual school grades, the Raven scores showed statistically significant correlation with all subjects, while the Brazilian TSI presented statistically significant correlation only with geography, history and sciences. Boys' mean scores were higher than girls' for both the Raven and the TSI Tests, but for the school grades girls performed better. In general, level of cognitive development was below that expected for children in the age-group analyzed.

Epidemiologia do desenvolvimento cognitivo de escolares em Jequié, Bahia, Brasil: procedimentos de avaliação e resultados gerais / Epidemiology of schoolchildren's cognitive development in Jequié, Bahia State, Brazil: assessment procedures and general results

This paper describes the methodology, applicability and utility of the Raven Progressive Matrix (Raven Test) and the Brazilian Intellectual Probe (TSI), comparing them with school achievement in a typical medium-size urban community of Northeastern Brazil. 388 schoolchildren (7-17 years old) were examined, with 371 Raven tests applied. Only 231 TSIs were completed, since 106 students were illiterate. School grades were obtained for all participants. A questionnaire evaluating school resources, and teacher profiles was answered by 200 teachers. Raven and TSI test scores were highly correlated (r = 0.53, p < 0.001), but both correlated weakly with overall school grade (r = 0.22, p < 0.001 and r = 0.12, p < 0.07 respectively). For individual school grades, the Raven scores showed statistically significant correlation with all subjects, while the Brazilian TSI presented statistically significant correlation only with geography, history and sciences. Boys' mean scores were higher than girls' for both the Raven and the TSI Tests, but for the school grades girls performed better. In general, level of cognitive development was below that expected for children in the age-group analyzed.